Concrete construction is enhanced by the insertion of metal rods such as rebar to improve compression and tension characteristics of the concrete structure. To accommodate joins, curves, and other structural elements, rebar must be shaped prior to installation to support the structural components of the concrete structure. Many rebar structural pieces are shaped prior to shipping them out to a job site, if the job is big enough to permit the builder to bear the cost of ordering pre-shaped rebar. Other construction jobs are either too small to bear this cost, or the shapes required are either too complex or unknown, or the builder simply does not want to bear this cost and will bend the rebar on site to suit the needs of the construction effort.
Bending rebar for emplacement in concrete at a construction site is a common practice. Tools for bending rebar are generally makeshift or simple in nature and construction crews depend on brute force to utilize the tools for bending rebar. Bending rebar may place significant strain on the muscles in the upper and lower back, and cause damage to a construction crewman when the tool is inadequate to the job or is used improperly.